Anxiety is one of the most frequent psychological problems that humans experience. It is estimated that anxiety related psychiatric disorders affect over 13% of the population each year in the United States. The cost of this individual suffering and the social burden of anxiety are significant. Effective treatment of anxiety and related disorders can significantly alleviate the suffering and distress associated with such disorders.
Treatment of anxiety and the related conditions of insomnia and convulsions is as old as recorded history, and the interventions are encyclopedic. While there are effective treatments, there is much need for improvement. The search for new anxiolytic medicines that meet acceptable standards of efficacy and safety continues.
In recent years this search has broadened to include an assessment of herbal sedatives and anxiolytics. These have been used in both folk medicine and phytotherapy for centuries, and continue to have widespread use in many cultures.
Scutellaria lateriflora, also known as Blue Skullcap or American Skullcap, (hereinafter S. lateriflora) is a perennial herb indigenous to North America and Europe. Long used as a traditional herbal remedy for a variety of indications, it is known to exhibit anxiolytic, sedative, and anticonvulsant effects. The use of S. lateriflora to treat anxiety, insomnia and related disorders has been one of its major therapeutic applications. The herb is typically used in the form of teas and tinctures. It can also be ingested in fresh or dried forms.
The leaves, stems and flowers of S. lateriflora contain a number of biologically active compounds. Nishikawa, et al. analyzed S. lateriflora, and found the principle phenolics in leaves, stems, and roots were baicalein and wogonin (Nishikawa, et al. Phenolics in tissue cultures of Scutellaria. Natural Medicines 53:209–213, 1999). Gafner, et al. screened dried above ground parts of S. lateriflora and identified the flavones baicalin and baicalein, as well as 5,6,7-trihydroxy-2′-methoxyflavone and its 7-0-glucuronide. (Analysis of Scutellaria lateriflora and its adulterant Teucrium canadense by HPLC-UV and HPLC-UV/MS, Tom's of Maine, PO Box 710, Kennebunk, Me. 04043, USA). Finally, a number of the flavones found in S. lateriflora have been reported to selectively bind with high affinity to central benzodiazepine receptor sites, leading to the view that the flavones exerts powerful anxiolytic and other benzodizepine effects in rats. (Medina, et. al., Overview-Flavonoids: A new family of benzodiazapine receptor ligands. Neurochem Res. 1997 22(4):419.)
While the prior art identifies certain compounds in S. lateriflora, it has not been demonstrated which compounds are therapeutically effective. Further, none of the known S. lateriflora extracts are standardized. In addition, the currently available commercial S. lateriflora preparations do not have adequate therapeutic effects, principally because concentrations of the therapeutically effective components are too low or are not sufficiently bioavailable.
There is a great need, therefore, for extracts of S. lateriflora that have rigorous standardization based on the presence of specific markers, and good quality control. There is also a need for extracts of S. lateriflora that have higher levels of therapeutically active components, better bioavailability, and demonstrated therapeutic efficacy. Further there is a need for methods of preparing these extracts, as well as for compositions containing these extracts. There is also a need for treatments for anxiety, insomnia, convulsions, muscle tension and spasm, and related manifestations and disorders using these extracts.